1. Field of the Invention
The present invention relates to a laser processing device, and more particularly to a laser processing device that has a high speed vibration unit and is capable of generating a three-dimensional cylindrical light beam.
2. Description of Related Art
Laser processing is generally used in various industries and is applied to fields of micro flow channel processing, panel cutting and even medical cosmetology. A laser beam used the laser processing has advantaged characteristics of small light spot and high energy facilitating precise processing in the aforementioned fields. A conventional laser processing device employs a laser source emitting a laser beam through a set of lenses. The lenses refract and focus the laser beam at a focus point for processing a workpiece. A maximum energy of the laser beam is only concentrated at the focusing point such that a processing depth is limited by the focusing point. Therefore, the laser processing device is merely able to process a surface of the workpiece instead of processing a deep and internal part of the workpiece.
To process a workpiece in different depths, the conventional laser processing device is adjusted to change the focusing point on the workpiece by focusing means. For example, a vertical position of the focusing lens is adjusted such that a vertical position of the focusing point is adjusted accordingly. Therefore, a depth of the focusing point on the workpiece is changed. However, during the laser processing, speed of adjusting the focusing point is slow and therefore prolongs the total processing period. A shallower layer of the workpiece is easily hardened before completion of adjustment of the focusing point to a deeper position, and shallower hardened layer of the workpiece forms a barrier and prevents a deeper layer from being removed out of the workpiece. The material of deeper layer in the workpiece may also be inadvertently sputtered out of the processing zone and forms a flange on the workpiece, so called “crater phenomenon”. The flange causes the surface of the workpiece bumpy and negatively effects the successive processes or results in defective products.
To overcome the shortcomings, the present invention provides a laser processing device with a high speed vibration unit to mitigate or obviate the aforementioned problems.